Absorption refrigeration



Patented- May, l9, 1936 UNITED STATES PATENT oFFics' :zrz'ztzrrm sft No Drawing. Application April 18, 1935,

Serial No. 11,004 g 4 Claims. (Cl- 252-6) This invention relates generally to a lvent circulating means are included, and automatic material and a refrigerant mixture for absorpt Controls y b providedtion refrigerating machines, both of the two-fluid The particular characteristics of such a matype and of the three-fluid type. chine are that the still operates at temperatures In absorption refrigeration there is required e a e normal t pe a u u 5 a solvent material adapted to remain liquid ple at 210 F. to 250 F.; and that the cooling throughout the operation of the apparatus, and unit opera es a t p u lower than n rma a refrigerant material adapted to have a liquid such as from 15 F. to 50 F. Various parts of and a vapor phasein the cycles of operation, h pp ra u dif r in h pr va i p r 10 adapted to be dissolved or absorbed in the solvent, tures and p e and b Pressure and 119m 10 adapted to be evaporated or boiled as a vapor perature determine the physical state of the free from the solvent mixture and from the solvent, refrigerantmaterial, whether gaseous or liquid, and adapted to be condensed from the vapor to 'and determine the solubility relations between a liquid. Numerous refrigerants and numerous .the refrigerant and the solvent material. It is, solvents are known, as well as successful comt e r V important that solvent 15 binations of'these'. the refrigerant materials be physically adapted Th two-fluid absorption a hi hav erfor use as individual materials in certain places tain mechanical parts which may be omitted'or and for certain functions, and that they be mutuwhich are not duplicated in three-fluid machines. ly adapted for ce u c i n when th y a In a three-fluid machine, there is in addition to in combination. Other qualities not essential 2 the two-fluid mixture, a body of inert gas-which t0 refrigeration, but pertinent to practical usage, is always gas, and which .does not to any subcontrol or limit the choice of solvent or refrigerstantial extent dissolve in any of the components ant, such as odor, viscosity, heat capacity, boilof the two-fluid composition, or in mixtures s p i fre in poi t, o ati ity, chemical 5 thereof. bility, reactivity, corrosive action, inflammabil- The present invention is directed to a new ity, toxicity, .solvent for absorption refrigeration, and to com- By considering the limitations herein set forth binations thereof with refrigerants. and suggested, I have been able to utilize diethyl- A particular object of the invention is the use iene ly l m n t yl th r m t xya ta as of diethylene glycol monomethyl ether methoxya solvent, for practical usage, in combination acetate as a solvent. with the refrigerant dichloromonofluoromethane,

Another object is the use of a combination of whi is little known 1 said solvent with the refrigerant dichloromono- The new solvent is herein named as di t y e fiuoromethane. glycol monomethyl ether methoxya'cetate, but it 85 Examples of the two-fluid a aratu in which m y be ha a r z d by t s a hy earbithe new solvent material and. the new combinal m h e How v r. in or r to leave tion may be used is disclosed in my tieen i no doubt as to its identity, its structural'gformula application Serial No. 651,306, filed Januar 12, is herein given: 7

1933, or in my U. S. Patent No. 1,895,698, issued cg ocmcn ococmocm.

40 January 31, 1933. Other examples may readily be cited, and will be known to those skilled in The refrigerant herein specified 5 l the art. monofluoromethane. However, in order to leave The two-fluid I apparatus above referr d to, no doubt as to its identity, its structural formula briefly described, comprises a still in-which a 1511mm given liquidmixture of solvent and refrigerant is heat- CHCIZF- ed to distill a y as & vapor-the refrigerant In the accompanying claims the invention is terial, a condenser whereinsaid vapor is 0011- set forth as a combination useful in absorption densed to a liquid state, an evaporator wherein refrigeration. It is to be understood that a simthe resulting liquid is vaporized at reducedpresple adulteration of the new solvent in its pure '5 sure to produce refrigeration, and an absorber in form, either by reason of commercial impurities, which vapor ofthe refrigerant material ohm or; by addition of lesser quantities ofother matetaining added heat units (acquired in the. rerial, useful also as solvent, is'permitted, and such frigerating process) .is again dissolved in the a composition is intended to fall within the scope solvent material. Suitable heat exchanging and of the present invention.

volving forty-six individual representative derivatives.

The refrigerants studied in conjunction with this group of solvents are: dichloromonofiuoromethane (CHClzF); trichloromonofiuoromethane (CChF) dichlorodifiuorometh'ane (CC12F2); methyl chloride (CHaCl) ethyl chloride (CnHtCl). 1

From this study it! has been determined that the solubility characteristics of one halogenated derivative of methane or ethane cannot be used to predict the solubility characteristics of a different halogenated derivative of methane or ethane.

With respect to the solubility characteristics of dichloromonofiuoromethane in these derivatives, the following observations are made;

Derivatives of ethylene glycol, ,diethylene glycol, triethylene glycol, tetraethylene glycol, hexaethylene glycol,.and trimethylene glycol, in

which both of the hydroxyl hydrogens have been replaced by relatively short carbon chain acyl, alkyl and alkoxy-acyl radicals, are good solvents for dichloromonofiuoromethane to form useful refrigerant mixtures.

Where the acyl, alkyl, or alkoxy-acyl radical 'consists of a relatively long carbon chain in a derivative of ethylene glycol, diethylene glycol,

triethylene glycol, tetraethylene glycol, hexaethylene glycol, or trimethylene glycol, the boiling point is raised but the solubility of dichloro- 'monofiuoromethan'e in the product is less than a corresponding derivative in which the acyl, alkyl, or alkoxy-acyl radical consists of a 511011816081"- bon chain.

Aromatic ether or ester derivatives of ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, hexaethylene glycol or trimethylene glycol are suitable but less satisfactory solvents for dichloromonofiuoromethane in refrigerant mixtures than a corresponding derivative in which a short carbon chain acyl, alkyl or alkoxyacyl radical is used.

The ester or ether derivatives of glycerol are suitable but less satisfactory, solvents for dichloromonofiuoromethane in refrigerant mixtures than the corresponding ester or ether derivatives of ethylene glycol, diethylene glycol,

triethylene glycol, tetraethylene glycol, hexaethylene glycol, or trimethylene glycol.

It may be predicted as a result of said extensive study that all of the following chemicals are good solvents for dichloromonofiuoromethane in refrigerant mixtures: I

p where Rand R are selected from the radicals:

' OCOCHzOCzHs.

OCI-h, 'OCzHs, OCOCH3, -OCOCH2OCH3, or

It may bepredicted as a result of said extensive study that in any one of the above indicated series of compounds where R or R is OCHs, the

product will be the better solvent for dichloromonofiuoromethane than where R or R is OCzHs; these compounds better than where R or R is .OCOCH:; these compounds better than where R or R is OCOCHzOCHa; it may also be predicted as a result ofsaid extensive study that in any one of the above indicated series of compounds where R. or R. is OCHa, the product will have a lower boiling point than where R or R is OCzHs; these compounds will have a lower boiling point than where R or R is OCOCI-Iar these compounds will have a lower boiling point than where R or R is OCOCHaOCI-Ia; these compounds will have a lower boiling point than where :R or R is OCOCHrOCzHs.

This application is a continuation in part of my prior application Serial No. 721,549, filed April 20,

The present application is generic to said earlier application andto applicant's co-pending application Serial No. 756,977, filed December 11, 1934, in which the solvent diethylene glycol monoethyl ether acetate is claimed specifically; generic to applicant's co-pending application Serial No. 756,978, filed December 11, 1934, in which the solvent diethyl ether of diethylene glycol is claimed specifically; generic to applicant's copending application Serial No. 756,979, filed December 11, 1934, in which the solvent ethylene glycol diacetate is claimed specifically; generic cally; generic to applicant's co-pending application Serial No. 19,596, filed May 3, 1935, in which the solvent diethylene glycol monoethyl ether methoxyacetate is claimed specifically; generic to applicant's co-pending application Serial No.

- 19,597, filed May 3, 1935, in which the solvent ethylene glycol monoethyl ether acetate is claimed specifically; generic to applicant's co-pending apwhich the solvent dimethyl ether of hexaethylene glycol is claimed specifically; and generic to ap-' plicants co-pending application Serial No.

' 33,709, filed July 29, 1935, in which the solvent diethyl ether of tetraethylene glycol is claimed specifically. I

This application is a continuation in part of my co-pending application Serial No. 756,982,

filed December 11, 1934, and is generic to it.

What I claim is:

- 1. A refrigerant mixture for the absorption type of refrigeration apparatus consisting of diethylene glycol monomethyl ether methoxyacetate as the essentially predominant solvent, and dichloromonofluoromethane as a refrigerant.

. 2. A refrigerant mixture for the absorption typeof refrigeration apparatus consisting of dichloromonofiuoromethane as a solute, and a solvent therefor consisting predominantly of a derivative of one of the glycols from the group consisting of the ethylene glycols from monoto hexaand of trimethylene glycol, said derivative having the two glycolic hydroxyl positions supplied with radicais from the group consisting of plication Serial, No. 19,599, filed May 3, 1935, in 5 I OCOCHzOCaHs. p

3. A refrigerant mixture for the absorption type of refrigeration apparatus consisting of diethylene glycol monomethyl ether methoxyaoehate as the essentially predominant solvent, and a volatile chemically stable halogenated hydrocarvolatile chemically stable halogenated hydrocarbon refrigerant-soluble in said solvent;

- 4. A retrigerant mixture for the absorption type of refrigeration apparatus-conslstingo! a a a 2, ,001 0cm, OCzHs. 000cm. ococmocm, and

-with radicals from the bon refrigerant as a solute; and asolvent theretor consisting predominantly of a derivative of one 01 the glycols from the group consisting of the ethylene glyools from monoto' hexaand of trimethylene glycol, said derivative having the two Iglycolic hydroxylposltions supplied group consisting of 001-13, OCzHs, OCOCHI, OCOCHzOCHr and OCOCH:OC2H5- qumn r. zmnonrsa. 

